By BRIAN STELTER; Amy Chozick contributed reporting.

Published: February 22, 2012

Following through on a pledge to carry more minority-owned cable channels, Comcast on Tuesday indicated its support for four such channels, including one from the music mogul Sean Combs and another from the former basketball star, Magic Johnson.

The first of the four is called BabyFirst Americas, a commercial-free channel owned and operated by Hispanic-Americans. The channel, which begins April 1, will include content for children under age 3. The second one, led by Mr. Johnson, is called Aspire and will start this summer. Aspire is described as an uplifting, entertaining channel for African-American families.

The third, a music and pop-culture channel led by Mr. Combs, who is known as Diddy, will be called Revolt and will start sometime next year. The fourth, pitched by the Hollywood director Robert Rodriguez, will be called El Rey and will offer general entertainment channel aimed at Latinos. It will start no later than January 2014.

Because Comcast delivers cable to 22.3 million households - one-fifth of all the households with TVs in the United States - its carriage decisions influence smaller cable providers. Even so, the four channels will still need to convince others to put them on, something that providers are generally reluctant to do.

''In our conversations with the channels, we were very clear that the selection by Comcast wouldn't guarantee their success, it would just give them a head start,'' said David Jensen, a vice president of content acquisition for Comcast.

When it was pressing the government to approve its proposed acquisition of NBCUniversal in 2010, Comcast repeatedly made commitments to carry more channels that were independently owned and operated. The commitments were made in part to win the support of organizations representing minority groups and to stave off concerns about media consolidation - given that, through the acquisition, Comcast took control of an array of NBC's cable channels.

Early on in the NBCUniversal acquisition process, Comcast pledged to add two independently owned channels a year for three consecutive years, or a total of six channels. It said that members of minority groups would have a ''substantial ownership interest'' in at least three of the six. Later on in the process, after advocates for minority media ownership criticized the proposed acquisition, Comcast stepped up its pledge: it said it would carry a total of 10 such channels within eight years, and said that four of the 10 would be majority owned by African-Americans; two would be majority owned by Hispanic-Americans; and two would be operated by Hispanic-American programmers.

With Comcast's proposed acquisition of NBCUniversal, and the need for government approval, advocacy groups said they saw a chance to address the under-representation of minority owners among cable channels.

Comcast has touted its carriage commitments as an improvement to its channel lineup and a better reflection of the markets it operates in. But the company declined to say how many of its subscribers would actually be able to view the four new channels. That's because some subscribers still receive analog cable, and the new channels will only be available to those who receive digital cable. ''We don't break out specific customer numbers for our service levels, but they'll be available to millions of homes,'' a Comcast spokesman said.

BabyFirst Americas has some of the same programming and some of the same investors as BabyFirstTV, channel for children under age 3 that is available through DirecTV and through an online subscription. ''BabyFirst Americas is the channel that is distributed in Latin America,'' Mr. Jensen said, and Comcast is bringing it to the United States for the first time.

Shows for both channels are made for infants, with large colorful images and a focus on skills development.

Mr. Johnson's channel, Aspire, will follow BabyFirst Americas this summer. ''Aspire will be a network that encourages and challenges African-Americans to reach for their dreams and will appeal to all generations,'' Mr. Johnson said in a news release.

Comcast said that it reviewed more than 100 proposals for channels before selecting the four that were announced on Tuesday. Separately, the company is working to expand the carriage of eight Hispanic channels; two African American-owned channels, the Africa Channel and TV One, and an English-language Asian pop culture channel, Mnet.

This is a more complete version of the story than the one that appeared in print.